Matrix



o. R. BRANDENBURG 2,187,260

MATRIX Jan. 16, 1940.

v Filed arch 23, 193s IN VEN TOR.

@auv WMM? l BY 13" WWORNEYS.

. `Patented Jan.` `16, 1940 `MATRIX Oscar R. ll'grandenlmrg,` Milwaukee," Wis.`

Application March 23, lsssgserii No; 70,249

;One object of the invention is to providewa e inatrixwhich will readily assume the shape of `various impressionsfand `hold the `shape during the formation of a model".`

furtherobject is to provide a variable .1Q investment box for making models,` soldering bridges; and `for `various other uses. e l

Another `object is to provide a matrix which willtconform exactly to the shape of any impre `"sion and WhichmayI be used repeatedly.

lo 1 :Further objectsare to reducethe time and cost ofmaking models in dental work,and to simplify the `setting up` workin model making.

Other lobjects will become apparent upon con- `sideration of the following description. 20, Two `embodiments ofthe invention are illusi trateduin` theflaccompanying drawing, in which: Fig.` 1 is a `plan View `of a matrix made in acf cordance with the present invention; v

Fig. 2 is a side View of the matrix-shown in Fig. 1; e

Fig. 3 `isa plan view of the.` matrix shown in` Fig. 1, as applied to an impression of the upper jaw;

Fig. `si `is across-section on the linef 4 4' of man3;` o

Fig. 5"is` a plan view of thematrix showing it applied to an impression of the lower jaw;

` Fig. `6 is a cross-section on the line 6`6 of Fig.5; e

Fig. '7 is a plan view of a matrix for use as an l investment box;

Fig.f8 is aview of the matrix shown in Fig.` '7,1L

showing it bent up to form an `investment box of thedesired size;.and e o Fig. 9 isa cross-section on the line 9--9 of Fig. 7, showing the box bent upvand containing a bridge which is in position forlsolderingin an investment compound. .i

Referring tothe drawing, in `which like numer-` als designate like parts throughout the several views, and referring particularlytoFigs. 1 to 6 i inclusive,` the matrix` box is shown as composed of a strip* I0 of soft flexible material such as rubber,` tapered at one end as shown at II, and provided with one or morefastening hooks I2 "atthe opposite end from the ltaper. The hooks have sharp points which projectinto the side of the rubber to hold the ends together asv shown clearly in Figs. 3 and 5. l

A `perforated core I5 of `soft ductile material 7 claims. (ci. 11i-34.1)

is embedded nl the strip lo. The core l5 is del signed to` `loelfiexible enough to permitthema-` trix to bereadily bent around sharp corners and so causethe soft material of the strip to make -a tight joint with such corners, andheavyenough 5 to overcomeany resilient tendency of the rubberl e o r;other material ofthe strip# il) to assume `its h form a monolithic unit.

ber forms a very satisfactory material` for." the outenstrip III,` that lead is best suited for the `original shape. The material of the stripfllll is H fused throughthe perforations of the core I5 to t o A1o 1 `In practiceit has been found that sponge frubi corel; and copper,` steelorpther metal maybe used for the hooks I2.` It is to be understood .1115"` 1 thatthis `invention is not :limited to these mad.

terials,` but that they are merely suggestive of t-whatjmay beused.`

Inuse,fanuimpression` of the upper jaw, as

shown in Figs. 3 andu4, oranimpression i8 of the lower jaw, as shown inFigs. 5 and` 6,.maybe n taken, and a matrix box may be formedby wrapping the` matrixshown infFigs. l and 2around molding compound is thoroughly set the wax Aof e the impressions I'I or I8 is removed giving a.` perfect m0del I9 or 2D of theupper or lower jaw, respectively. l

A second type of matrix is shown in Figs.` 7,

8 and 9. Referring to theseiigures,it will be seen that 4the matrix comprises a `rectangular strip 25 of soft fiexible material cut diagonally `ir'rvvard from the four corners as shown at 26 and having a perforated core 2'! embedded in "the material 25. The core 2'If`is spacedinwardly from the edges of the strip25 and from the cuts 26.

The same material may be used for this matrix `"0 In using this matrix the four edges of the strip `25 are bent up toforma rectangular box such 4, l as is shown in Fig. 8. The box may be used for 1 forming a mouth model of'plaster of Paris similar` asfor the one shown in Figs.` l and2.

to the models I 9 and 20 shown in Figs. 3 to 6 inclusive, or the box maybe filled with invest` in the ment compound for soldering a bridge 3B manner shown in Fig. 9. f

It will be noted, in respect to the matrix shown inFgs. l and 2, that itreadily adheres to the side ,reused anindenite number of times. l

. of the impression and conforms toany small `ir e -UNTEDSTATS PATENT @we The matrix shown in Figs. 7, 8 and 9 may be formed into any size box desired with a self-contained bottom, and may be used for a'variety of purposes.

Having thus described the invention it will be apparent that it is susceptible to various vchanges and modifications of both form and material.

' .'said strip of ductile material being of sufficient stiffness to cause the matrix to retain the shape of the periphery of the impression during the casting operation -in the mold.

2. -A-matrix, comprising, astrip-of soft flexible material and va perforated strip of ductile material-embedded in the irstnamedrstrip with the material -of -the first 'strip fused vtogether' through said .perforations said strips beingadapted to be shaped around the periphery of an impression or the like and to form therewith a mold, said perfovrated `strip being ofl suficient stiffness to cause the matrix to retain the -shapeof the periphery of the impression during the casting operation inthe mold. o

3. fAmatrix, comprising, astrip of soft flexible vmaterial a .strip 4offductile lmaterial embedded in saidfrst :named strip, said strips being adapted Vto .be shaped to conform to the periphery of an impression .or x,the like and to form therewith a mold, said flexible strip having a tapered end to permit @the strip to conform closely to the impression vat all points, and said strip of ductile material ybeing Iof ,sufficient lstiffness to `cause the .y matrix :touretainthe shape of the periphery of 4"the :impression during the casting operation in zthe mold.

4. A matrix, comprising, a strip of soft flexible material a strip of ductile material embedded i'n said flexible material, said strips being adapted to be shaped to conform to the periphery of an impression or the like and to form therewith a mold, said strip of ductile material being of sufficient stiffness to cause the rst strip to retain the shape of the periphery of the impression during the casting operation in the mold, and means to retain the matrix on the impression.

5. A matrixcomprising, a strip of .soft iiexible materiala strip of ductile material having perforations therein embedded in said iiexible strip with the material of the flexible strip extending Vthrough said perforations, said strips being ladapted'to be shaped to conform to the periphery of an impression or the like and to form therewith a mold, said strip of iiexible material having a tapered end to permit the strip to conform closely to the impression at all points, said strip of vductile -material possessing sufcientlthickness tofcause the matrix to retain the shape of the jperiphery operation in the v impression during the casting. .of .the mold, and .means to retain the matrixon the mold.

6..,A matrix of ithe character described com- .prising ,a strip Aof :sott flexible .material and a strip of ductile material :embedded therein, said strips having La ,plurality of .outs .extending throughfsaid materials toward the central yportion thereof to enable the .matrixto be .shaped .to 'a desired fform.

:7. A matrix of the character Adescribed .comprising a stripof soft ,flexible'materialand .a per- ;foratedstrip of ductile .material Yembedded infsaid flexible material with the flexible material passing through said .permita-tions, said `strips .having cuts through bothmaterials extending ,toward .the central portion of saidstrips for the purpose set forth.

OSCAR R. BRANDENBURG. 

